REDONDO BEACH, Calif., Jan. 18, 2010 (GLOBE NEWSWIRE) -- The first primary mirror segment of NASA's James Webb Space Telescope has met flight specifications at ambient temperatures, the result of a process that has been six years in the making. Northrop Grumman Corporation (NYSE:NOC - News) is leading the design and development effort for the space agency's Goddard Space Flight Center.

“The mirror segment, an engineering development unit, was successfully polished to an accuracy of less than 20 nanometers, or smaller than a millionth of an inch. The process, called cryo-null figuring, ensures that when the mirror reaches cryogenic temperatures, it will change its shape into the exact optical prescription needed for its mission.”

"To achieve the exacting specifications for the mirror, Perkin-Elmer used an optics template, a tubular array of smaller mirrors and lenses linked by connecting rods, to guide the grinding and polishing processes. When the Allen committee tested this template assembly, it found that there was a critical error of 1.3 mm (0.05 in.) in the placement of the template's components. The Hubble mirror was carefully fashioned to match exactly this error in the template." (link)

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